When a biopsy is performed, a small slither of skin is removed, under local anaesthetic, to determine if a mole or rash, for instance, is something more serious, such as cancer.

But while the patient is assured the procedure is completely safe, researchers have discovered that nearly a third of all biopsies have complications, such as wound infections.

They made the discovery when they tracked the progress of 100 patients who underwent a skin biopsy at a dermatology ward in a university teaching hospital. Wound complications occurred in 29 of the cases, and all but two were caused by wound infection.

The patient was more likely to suffer complications if the skin biopsy was performed below the waist, if the procedure happened in a hospital ward rather than in the outpatient unit, if the patient was a smoker and if he or she was taking corticosteroid drugs at the time.

(Source: Archives of Dermatology, 2007; 143: 1267-71).